The non-invasive high-intensity focused ultrasound has been coupled with high resolution MRI to provide precise, consistent treatments that can be monitored in real-time. The development of phased array transducers allows for tightly focused treatment volumes and for the ability to compensate for distortions by tissue inhomogeneities. The landmark advance in MRgFUS for neurosurgeons occurred as the ability to sonicate through the intact cranium was achieved with phased array transducers and acoustic modeling using CT reconstructions of the skull. By coupling HIFU with MRI, detailed treatment plans can be generated and intra-procedure real-time monitoring is available. Standard MR sequences have been shown to reliably predict tissue damage during thermal lesioning with ultrasound. The precision of the technology has already been demonstrated in animal models and is currently being investigated in humans with brain tumors and neuropathic pain syndromes. Unlike stereotactic radiosurgery, the treatment can be monitored continuously in real time with MRI and MR-thermography. We anticipate that a MRgFUS non-invasive thermal lesioning is similarly as safe as DBS (or other current procedure and will provide several years of benefit through reduction of contralateral motor symptoms and potential medication side effects in ET, while still permitting subsequent treatment with DBS should that become clinically desirable.